E. Khomenko and M. Collados EFFECTS OF PARTIAL IONIZATION IN THE PHOTOSPHERE AND IN THE CHROMOSPHERE E. Khomenko and M. Collados
Approximation of magnetohydrodynamics + Fully ionized Coupled by collisions Single fluid description
photosphere chromosphere
Approximation of magnetohydrodynamics Multi-fluid approximation + B + Fully ionized Coupled by collisions Single fluid description Weakly ionized Less coupled by collisions Sunspots and chromosphere Best valid in the deep photosphere and convection zone
Equations of Magnetohydrodynamics
Equation for individual species
Combined quasi-MHD equations
Diffusivities
Conversion of magnetic to thermal energy
Z = 1000 km 900 G 750 G 600 G 450 G 300 G
Z = 1000 km
Conclusions Collissions with neutrals (ambipolar diffusion) can lead to a significant temperature rise (~ 2000 k) within minutes at chromospheric level Important plasma motions can appear during the heating process